This invention relates to storage and handling of media cartridges and more particularly to an media transport element for storing and handling optical disc cartridges.
The storage of data in magnetic media, such as floppy discs or tapes, is well known. However, optical discs have been found to be highly advantageous over the magnetic media. This is so because the optical discs have high degrees of integrity and data storage capabilities together with a high level of sensitivity as well as environmental toughness.
The optical disc cartridges which hold laser discs are high-density data storage media. Currently, the media hold 1.3 gigabytes per cartridge which are soon approaching up to 3 gigabytes in the very near future. The cartridges perform the function of protecting the discs from dust and dirt. Optical discs within cartridges are readily available in the marketplace as from Sony Corporation of Tokyo, Japan.
High-capacity (1.3 gigabyte) optical disc drives are currently available in the market such as the Ricoh 5060E, Sony SMO F-521, and IBM 0632 C2A. Typically, optical disc cartridges must be removed and inverted or flipped with reinsertion for the drive to read the other opposite side of the disc within the cartridge. This is because most drives have only one laser thereby requiring the disc to be flipped over or inverted for reading or writing the other side of the disc. However, optical disk drives are beginning to be marketed and soon will be prevalent that will have more than one laser which will allow quick access to the storage data on either side of the optical disc media. In the present invention, the reading and writing of data storage on the optical disc within the cartridge is performed by the drive under the control of a host computer.
Most optical disc cartridge handling apparatuses on the market use several belts and pulleys to perform the functions of: positioning the cartridge transport mechanism adjacent either the optical disc drive or an optical disc cartridge store; flipping the optical disc cartridge to its other side; and inserting and removing the optical disc cartridge in the optical disc drive or cartridge store. Such belt and pulley arrangements are slow, subject to frequent adjustment, and generate substantial amounts of dust within the optical disc handling apparatus. The dust generated by these belts and pulleys has required the optical disc cartridges to be stored vertically within the cartridge store, in order to avoid accumulation of dust on the cartridge. In turn, this cuts down on the storage space available, as most housings are preferably taller than broad.
In order to transport a cartridge between media store locations and an optical disk drive, a media transport element is first positioned at a source storage cell containing a cartridge to be retrieved. A gripper is activated to engage the cartridge and retract it from the storage cell. The media transport element is then positioned at a destination cell and the gripper is again activated to insert the cartridge in the storage cell and release it.
It is desirable to employ two or more grippers in a single media transport element. Using multiple grippers minimizes media transport element travel because plural cartridges can be transported simultaneously.
A disadvantage of prior art, multiple gripper media transport elements is that discrete gripper drive systems are used to control gripper positioning. This requires a duplication of hardware components and associated control system support functionality. The result is increased complexity and cost, as well as reduced response time due to increased media transport element mass caused by hardware and control system redundancy.
Other prior art media transport elements, while having multiple pickers, did not allow the multiple pickers to be positioned both simultaneously or alternately by the media transport element. Consequently, multiple cartridges could not be simultaneously positioned within the media transport element for securely holding the cartridges during positioning of the media transport element.
There is a need for a media transport element having multiple gripper capability but without the attendant disadvantages of multiple gripper drive systems. Additionally, the media transport element must have the capability of positioning multiple cartridges within the media transport element either simultaneously or alternately. The media transport element should have the capability of using only one of the multiple grippers if so desired.